gk1

Tirerack is now offering the RS7 21" PZero PZ4 in stock SQ5 size 255/40R21.
It has their PNCS noise cancelling foam and sport tread pattern.
Pirelli P Zero (PZ4)

Pricey, but the newest kid on the block. Still cheaper than the non-sale price on the Dunlops.
I never had much luck with Pirelli tires but thought others might like to know.
My emails to Michelin regarding PSS in this size went unanswered.

gk1

For anyone interested in tire weights.
Brand new OE Dunlop SP Sport Maxx GT 255/40R21 weighs 31.5 lbs.
Very close to the Tirerack spec weight of 31 lbs.

SuperQkc

Unfortunately these NEW kid on the block "PZ4" tires also have a significantly lower mileage rating due to the noise cancelling Foam in the compound. Newer is not always better.
PIRELLI
P ZERO (PZ4)Max Performance Summer

• Size: 255/40R21 102Y XL
• R01 Audi, PNCS, Sport
• Sidewall Style: Blackwall
• UTQG: 220 AA A

PIRELLI
P ZEROMax Performance Summer

• Size: 255/40R21 102Y XL
• Sidewall Style: Blackwall
• UTQG: 300 AA A

shokhead

Same price as the Dunlops is looks like.

tmfstyle

Is the demand for all seasons not significant? Presume 265/40's all seasons would be fine on stock 21's but kind of annoyed no all seasons available in stock size.

shokhead

Well here in SoCal I won't use all season again because they do neither dry or wet great. Both just ok at best.

BG SQ5

Not sure why anyone would run the stock size when 265/40r21 fits. I couldn't bring myself to run an a/s on a SQ during the summer either.